Electrons are particles which carry a negative charge. They, along with protons and neutrons, make up atoms.

As far as the science goes today, electron is considered a fundamental particle classified as a lepton. Other leptons are muons and tauons. These three fundamental particles also have their neutrino counter parts - electron neutrino, muon neutrino and tauon neutrino.
Other class of fundamental particles are called quarks (up, down, charm, strange, top and bottom). Quarks and other leptons are held together by high energy gluons to form other particles, e.g., protons and neutrons.

Photons

Electrons are sub atomic particles of negative charge

Electrons are the glue of matter

ELECTRONS ARE ELCTRO-MAGNETIC WAVES